1. Field of the Invention
This invention relates to valves and in particular to valves having soft movable seating members.
2. Description of the Prior Art
In U.S. Pat. No. 3,444,605 of Carl Bolling, which patent is owned by the assignee hereof, a needle-type valve is shown having a frustoconical movable seating portion adapted to engage a seat defined by the body of the valve through which one of the flow passages of the valve opens. The stem carrying the seating portion is threadedly adjustably carried by a bonnet portion of the body whereby suitable manipulation of a handle attached to the stem effects movement of the movable valve portion toward and from the seat to control fluid flow through the valve.
In U.S. Pat. No. 2,277,750 of Melvin Enquist, a valve is shown utilizing inner and outer metallic rings with an intermediate rubber ring vulcanized to the metal rings.
John Tannock, in U.S. Pat. No. 2,851,243, shows a jumper for domestic and industrial water taps, valves and the like having a head molded integrally to a stem formed of a plastic material, such as polyvinylchloride or polythene. The head is deformed radially outwardly into a surrounding space limited by an outer frustoconical edge portion of a constraining member.
In U.S. Pat. No. 3,290,002, Richard Self discloses a flow control valve having a Teflon sleeve 42, a portion of which flows into the bore of an outer retainer while being effectively encapsulated within the retainer at all times.
Myles Murray, in U.S. Pat. No. 3,326,521, shows a needle valve having a tip formed of rubber or other resilient composition with a metallic sleeve press fitted onto the valve body and extending about an outer portion of the tip.
In U.S. Pat. No. 3,698,427, Frank Baranowski, Jr. shows a valve wherein cold flow of the valve seat engaging portion of the valve element occurs so as to define the final configuration of the movable valve element.
A number of faucet patents show the use of rigid sleeves surrounding the deformable, movable seating portion of the valve. Thus, Albert Fuller, in U.S. Pat. No. 3,135, shows a faucet wherein the India rubber plug is encased in a metallic shield. Henry Mueller, in U.S. Pat. No. 950,186, shows a faucet wherein the Fuller ball is held in place between a rigid collar on the stem and a nut screwed onto the extremity of the stem. A tubular thimble formed of brass fits snugly about a flange on the ball to prevent undue expansion of the ball.
William Stewart, in U.S. Pat. No. 1,266,340, shows an expansion control device for elastic valves wherein the Fuller ball is enclosed in a metal cap designed to enclose the rear end as well as the sides of the ball. The cap is provided with a number of perforations permitting some expansion of the ball therethrough.